Bearing pile



March 17, 1953 J. P. EMSHWILLER 2,631,435

BEARING PILE Filed May 5, 195o m3 Wy/MW ATTOR N EY Patented 'Max'. 17, 1953 1.]UN`1TED STATES PATENT 1 OFFICE .1. 410 Claims. (Cl.61`-53) y, .(Granted under Title 35, U. S. Code 1(1952), l sec. 266) v.Theinventienedescribed herein may be manu- ;efactured and used by orfior thefGovernment of thenUnited 'States for governmenta1. ;purposes Without payment to me ofyany royalty thereon in-ac cordance with-the -provisions ofs.` the act of April 3D, 1928 l(chflGO, 45 Stat. L. 467).

* 'gIhis invention relates to pilingand a method .of'driving piling.

It isl ani object of this invention to provide a .f appile *whichV can beexpanded at1one or more prea determined locations along its length.

' It is another object of this invention to provide .1.a vpiles having increased pulling resistance and load supporting capacity.

.iig-,Other objects oradvantages will be apparent or appear hereinafter.

, uThese objects and'. advantages are `accomplished inaccordancefwiththis invention by a pile in- ..:;.cludin g a pipe vor tube having a plurality offsubstantially` equal longitudinal slots symmetrically disposed in a zone about its periphery, an inner zg- 1sleeve.Y memberone end ofwhich is `secured to .said1pipe andwhich isfreeat its oppositev end, a v-positiveqstop for saidvsleeve secured within said fr.. pipe at a point away from said free end-not fur- .;fther than about one-half the length of Vthe slots.

v The inventionfwill be better understood by egreference tofthe gures of the drawing where i there -are shown presently preferred embodiments ofthe invention. Figure 1 is a partly sectional- Zed Aviewin elevation ofa slottedzone along the .;;;length oa pipe pile, Figure 2` is a vertical partially sectionalized view of an expanded pile. Fig.' 3is a viewv like Fig. l of a modication, and

Fig. 4 is an elevation of a further modification.

Referring now to Figures 1 and 2 there is shown a section of a tube or pipe pile I6 at the point Aalong its length where its expansion is desired. Any type of hollow pile can be used in this connection regardless of cross sectional shape. Cut into the pile are a plurality of slots It is presently preferred to cut these slots .so that their longitudinal axis is substantially A `parallel to the longitudinal axis of the pile, be-

cause a greater degree of deformation can be vobtained with shorter slots. e Torsional reactions .are also eliminated thereby preventing any tendency of the segments of the pile above and below the slots to rotate with respect to each other. Further it is considered preferable to have `the slots symmetrically disposed about the periphery of the pile so that uniform expansion will occur.

The amount ,of expansion ofthe pile is limited by the length of the slot and length oftravel of the free end ciz the Vthe same application by .varying-the length of `the slots, the width 0I" the slots, .l.and.,.the.cweb

vtlfiicliness |2 between the slots. .While in.,some

.instances it would bev possible to have.the slots vprefabricated in the piling, the factthattheir size will be varied by structural limitations it is preferable to slotthepile after determinirigtheir proper size and location.. .Slotting can ber carried out by any of the manymethods Aknown vtothe art; for example, Oxy-acetyleneA torches.

lStill referring to the drawings thereis shown an inner sleeve member i3 withinthe slotted zone. The sleeve is employed to prevent inward buckling of the slot webs vduring driving and to positively limit the expansion at some predetermined position, and to insureconoentricV alignment 'of the tube above and below the slots after expansion. The sleeve member is secured at one 'of its ends yto the piling. In theembodiment shown 'in Figs. l and 2 of the drawings, the lower "sleeve end" |3| and the lower end of .th'e' pile IBI are secured by a weld iii- However any other means of securing the pipe and sleeve can be employed, for-example, riveting, bolting, threadingand the like?" The opposite end of the sleeve member 1| 32 is not secured to the piling; hereinafter this end jwill sometimes be referred to as the free end 'of the sleeve.

A means for arresting movement of the inner sleeve member is secured within the pipe; A 'rigid ring |5 welded in the pipe `has been found to be a satisfactory. means for. this ypurposebutlother l means can be substituted. The .ring l5 ,forms a shoulder |5| which. when .engaged by sleeve Tend |32 willarrest' relative movement of` the sleeve I3 with respect to thev pile It and also'frelative y movement of the pile end IDI withrespect'tdthe pile head |32 when the slotted zone is ,expanded to the desired degree. When the pile is unex- ,.panded, the distance between theffree sleeve end shoulder is about one-halfthe Iengthpr'theslOts then the maximumv buckling (i. effpile expansion) of the web members |2can occurf-The extent of lweb v`buckling can be controlled 'tosuit various drivingconditions;vr ln many applications it is preferable to secure weblbuckling (pileexpansion) such as shown in Figure 2. In that particular example the distance between the free end |32 and the shoulder l5! in the undriven pile was about one-fourth the slot length. It is apparent therefore that the extent of pile expansion can be controlled by properly establishing the distance between the sleeve end and positive stop.

As shown in Figure 1 the sleeve |33 has several parts or openings cut through it lying substantially within the slotted zone of the pile. Such parts can be employed to fill the bulb formed when the pile is expanded with concrete or other grouting material. This practice Will result in piles of even greater strength and resistance.

Another embodiment of the invention as illustrated in Fig. 3 involves securing one end of the inner sleeve member I3" within the pile I0 at some point above the slots il and having its lower end act as the free end capable of coming into engagement with the positive stop means l5', i. e., a, mere transposition of the parts shown in Figure 1.

Another embodiment of the invention involves securing expandible tips -and/or intermediate expandible sections to concrete or w-ood piling to form a composite pile.

The driving of the piling of this invention will vary with the nature of the application. If they are to be driven to bed rock before expanding G the pile, and in being so driven the pile passes through a soil strata cap-able of causing the pile to expand, then it is preferable to employ a pilot pile extending completely through the hollow piling and sleeve member so that none of the driving forces affect the web members. When bed rock is reached the pilot pile is withdrawn, and the pile driving hammer is permitted to operate Iagainst the pile head. These forces will cause the pile to begin expanding (i. e. buckle the web members) because the slotting has weakened the zone of the pile which is desired to be expanded. By continuing driving on the pile head, expansion of the pile will continue until the free end of the inner sleeve comes into engagemeni-l with the stop means. At this point expansion is complete and the pile end cannot move relative to the pile rhead. A pil-ot pile is also of use in driving through temporary obstructions. In driving to rock through soft soil, the pilot lpile is not required.

Under certain soil conditions and when a pilot pile is not used, the frictional resistance of the pile to driving will be sufficient to cause expansion of the pile Without reaching bed rock. This can also be accomplished by closing up on the opening of the lower end of the pile thereby adding end or point bearing to friction resistance to cause expansion. It will be apparent that it is possible to design the slot and webs of the piling so that expansion will not occur until an elevation has been reached which will provide the desired pulling and load supporting characteristics.

In some instances where the piling is to pass through various types of substr-ata it may be desirable to have the piling expanded at more than one elevation. This can readily be done as indicated in Fig. 4 by putting a plurality of slotted zones Il" along the pile l0 at the predetermined points where expansion is desired. In such instances expansion of the various zones can be accomplished simultaneously lor separately at the various levels.

The expanded piling -described herein will give greatly increased resistance to pulling forces and increase the load supporting capacity of the piling even in poor soil conditions.

While the piling as particularly described includes a movable sleeve and a positive stop for said sleeve it is possible in certain applications to eliminate these elements and merely use a slotted pile. Such piles can be expanded by driving to bed rock, permitting the end resistance of the rock to elect pile expansion.

Expansion of the pile at one or more of the slotted zones can also be -accomplished by mechanical means such as are Ydisclosed in my copending applications Serial No. 160,201, filed May 5, 1950, and Serial No. 160,203, filed May 5, 1950.

Since many widely diiering embodiments of the invention will occur to one skilled in the art, it is not to be construed as limited to the specific details illustrated and described herein, and various changes can be made therein without departing from the spi-rit and scope thereof.

What is claimed is:

l. A pile including a ypipe having a plurality of substantially equal longitudinal slots symmetrically disposed in a zone about its periphery, an inner sleeve member at least partially within said slotted zone one end of which is secured to said pipe outside said slotted zone and which is free at its opposite end, a positive stop for said sleeve secured within said pipe at a point away from said free end not further than about 1/2 the length of the slots.

2. A pile including a pipe having a plurality of substantially equal longitudinal slots symmetrically disposed in a zone about its periphery, an inner sleeve member secured to said pipe at a point below the bottom of said slots and free at its upper end, and a -positive stop for said sleeve secured within said pipe at a point above the free end of said inner sleeve member not greater than about ya the length of said slots.

3. An expanding pile including a pipe having a plurality of substantially equal longitudinal slots symmetrically disposed about its periphery, an inner sleeve member secured at its upper end at a point above said slots to said pipe and free at its lower end, a positive stop for said sleeve secured within said pipe at a point below the lower end of said sleeve and not further from said free end than about 1/2 the length 0f said slots.

4. The pile of claim 1 having a plurality of slotted zones along its length.

5. A pile comprising an open bottomed hollow tube of a strength adapting it to be driven to bearingin terrestrial strata and having a plurality of longitudinal slots symmetrically disposed in a zone about its periphery and dividing said zone into webs capable of resisting bulging under the driving or" the pile until a predetermined bearing resistance is encountered and of then bulging under continued application of driving force to expand the pile without loss of bearing on the underlying structure, whereby the driving of the pile through overburden involves only a minimum displacement of overburden and hence a minimum bearing resistance until a strata is reached offering the desired bearing resistance to the limited annular end area or" the hollow pile.

6. A pile comprising a hollow tube of a strength adapting it to be driven to a bearing in terrestrial strata and having a plurality of longitudinal slots symmetrically disposed in a zone about its periphery and dividing said zone into webs capable of resisting bulging under the driving of the pile until a predetermined bearing resistance is encountered and of then bulging under continued application o driving force to expand the pile without less of bearing on the underlying structure, said pile having Within its tube initially spaced abutment means brought into engagement on the buckling of the slotted portion for limiting such buckling and transferring vertical loads applied to the top of the pile to the underlying bearing strata.

'7. A pile vaccording to claim 6 in which said abutment means comprises one abutment element carried by the tube and spaced from one end of said slotted zone and a second abutment element compressing a sleeve secured to said tube beyond the other end of said slotted zone and extending across the slotted zone in the buckled condition thereof.

8. A pile according to claim 6 in Which said abutment elements are initially spaced apart by a distance not greater than about one-half the length of said slots.

9. A pile according to claim 7 in which said sleeve is perforated to permit lling material to pass therethrough between the interior of said sleeve and the space Within the expanded slotted portion.

10. A method for installing piling that comprises slotting a hollow open bottomed metallic pile in a zone about its periphery with slots or" a frequency and length predetermined to impart to the slotted section a resistance to buckling to correspond with a desired bearing resistance, driving the pile until such bearing resistance is encountered, and thereafter applying additional driving force to said -pile to cause said slotted zone to expand and buckle While maintaining the attained bearing resistance.

' JOHN P. EMSHWILLER.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 1,224,926 Hindmarsh May 8, 1917 1,746,848 Bates Feb. 11, 1930 1,951,643 Bald .Mar. 20, 1934 2,269,646 Burke Jan. 13. 1942 

